Apparatus for determining pressure distribution on airfoils and the like



E K w um K E ml v T l. v f U D7 N1 l i E A K H. S W K LN KM md K K K We H Mm K N o Dec. A11, 1945.

4 sheets-"snaail 2V APIARATUS FOR DEIERMINING PRESSURE DISTRIBUTION IN V EN TOR.

K Arra #Fys Dec. ll, 1945. H. M. HEUVER 2,390,534 APPARATUS FOR DETERMINING PRESSURE DISTRIBUTION 0N AIRIOILS AND THE LIKE Filed Nov. 17, 1944 4 Sheets-Sheet 5 mba-I Afro fia-ys Dec. 11, 1945. M. HEUVER A 2,390,534

' APPARATUS PORDETERMINING PRESSURE DISTRIBUTION oN AIRFoILS AND THE LIKE Y Filed Nov. 17, 1944 4 sheets-sheet 4 /Oh4 76 64j.

aoc/" l I INVEN TOR. r

Patented Dec. 11, 1945 smits Parel-vr orsi-c APPARATUS FOR "DETERMENING `PRESSURE ISTRIBUTI'ON "0N AIRFOIDS THE ('Granted wunder the act of March 3, 11883, -as amended Apri1;39,1921i; 3709. 7F51.)

l Rein-Mention rdescribed herein may be :manumxliured :and :used by or for the Government for eduernmentafl purposes, without -ithe kpayment to me-tof anyroyaltytnereom t *Imis invention relates to apparatus-iorlexpediting the `determination 'of pressure distribution on the surfacesof' airffols or thelike. It is particulazily applicable :for recording the iresults of `--win-d .tunnel tests. l y

An object .of the invention iis to provide means tor indicating and lrecordingthe pressure on 'the surfaces of `a wing or==the like at a plurality of pointssimultaneously Another -obect -is to `so construct and arrange the controlsofthe apparatus-that yindications of thegpress-ures at the desired points over the `entire surface of an -a-irfoil may be had by-"'the .operator without `moving from hi's positionat "the control board. "N Y `Inasrrmcgh as, for the purpose of proper analysls it is usually desirable to determine .the` pressure atV `not less than several hundred points on lthe surface of a `single wing, and 'inasmuch .as a multiplegmanometer having a tube for each oi the several hundred points would' be too costly Aas well as too cumbersome, it ls'another object of this invention to divide the points to be pressure tested into groupsJ provide a manometer with av number of tubes equal to the number in one group then `provide a multiple valve means for selectively connecting one after the other of the groups to themanometer.

`Other objects and advantages will become evident as theinvention is described' ,in detail and reference is had .to the drawings, wherein:

Fig. lj is a top plan View of a valve block which ycontains a group of valves all closable by the application of pressure to a single connection, a portion .of the view being broken .away to' the line "l-l of Fig.. 2V to show the interior construe` lon.

Fig; 2 is a transverse section taken at .2-2 of Fislshowing the means employed for'shutting oft a group of' tubes ,which extend `from the manometer tubes `to points `on the wingwnioh .are tobe evaluated;

Fig. `3l is a transverse ,Section taken at .3-3 of Fig- 'I ,Showing the manner .in which the several parts of the valve block .are secured in place,

Fig. i isa perspective view of thatV `portion of the apparatus which minste-neu in the winatun; nel, namely, the Wing model, valve blocks containing ja number of valves; equal to the points on the. `being tested .and a multiple.

,eter having .tubes egual to. the number lof valves ineaclngroup.M n t t l A5 .is .a front View .of .the selective valve mechanism which is installed in the control room for operating the `groups .of :nanometer valves.

Fig. 6 isa .vertioalsection taken at p-,Sof Fig. `5 showingone .bank of theselector valves.4 t

Like numerals refer-to like partsv throughout thetdrawings. p A VReferring now to the drawingsy` 'a valve block L0 has a longitudinally extending channel `1,2 and a smaller Channel "I4 inthe bottom of the first channel (see Fig, 3.),` Channels YI2 and I4 ex` tend the entire length of the valve `block and la cover J6 isfsecured over themby screws 18,. A plurality .of small vcircular V openings extend cross- Wise through thevalve'blocl'for 'the flexiblevalve .tubes Zwlrichhave a length equal 'to the Width of .the block; The lower corners of the 'block lll are cut away for the valve tube clamping strips 22 which are `provided with .adjusting screws 24 having nutsZ. Tubular metal nipples 2B `are Vin `serted Iin one of the endsy of the rflexible Valve tubes 201, while similar nipples 30 having Y end connections I."szand 3l are. inserted in the other ends of the valvetu'bes. j Tigh'tening ofthe screws 24 sealsthe metal nipples 23 and 3U inthe `ex-v `ible vvalve tubes 20 -andholds the flexible valve tubes 2l() positioned-in the 'block Il) with vtheir mid-:portion exposed where they cross theol-1annel Hl; A relative-1y large valve shut-off hose 36 of fiexible material isV normally held. by a flat spring "38, to an oval' shape `which substantially lits the larger channel I2.` The ends of the valve blockV 10 are closed by vrend plates 411 which are attached bly screws 42. End plates 40 .havefintegralnipples' 44 extending inwardly; the ends cf-fthe hose being bound `to :the fnipplesas at 46. The :end :plates are internally .threaded `tor the tting y48 by lwhich oneofrthe pressure lines 5l fisfconnected to supply pressure lto the interior of the :shut-oil hose 3.6,-the :tapped opening in the end plate at. the opposite end of the block Abeine' plugged .as at 4:9. Pressure applied to fthe valve shut-oit ifhose 3:8 willexpand it into a round cross section l.whereby the flexible val-ve tubes 28 will heclosed l The foregoing, taken in conjunction withligs. 1, 2, and 3, completes the description of one valve block and itsv associa-ted parts which, for purposes cf fnrrtherdiseuss-ion, may hereinafter be referred to as 1a valve block assembly and be broadly desiena-ted by the numeral 50. It :should be noted that the valve block arrangement shown lends itself particularly to the present .invention or t9 shownbut have a depth equal to that of both channels I2 and I4 taken together. A group of valves which are opened or closed by manipulation of a single one of the selector valveshereinafter described may comprise only one valve block assembly 58 or it may comprise several of these assemblies connected in series.

In the perspective view Fig. 4, there is shown a test wing 52 together with the several valve block assemblies 50A, 50B, etc. and the multiple manometer 54 composed of individual manometer tubes 54a, 54h, 54e, etc.,'the several points on the wing to be evaluated being connected through the several valves to the individual manometer tubes by metal tubing.

For purposes ofA illustration only, the surfaceof the wing is shown` as being divided into twelve sections, namely, 56a. 56h, 56e, etc., with twenty eight openings 58a, 58h, 58e, etc., in each section, partv in the top and part in the bottom. The shut-off hose 36 of two assemblies 58A and 58a, etc., are connected in series by the tubes 68a, 68h, etc., the two blocks together having at least as many valves as there are points 58a, 58h, etc., in one group of wing openings. Y

The wing 52, valve block assemblies 58 and multiple manometers 54 are connected in a relatively close group as shown, and may be together contained in the wind tunnel, but the tubes 5|a, 5|b, 5|c.etc.,f which 'emanate from the flexible shut-off hose 36 may preferably be extended to a control room outside the wind. tunnel, the tubes 5|a,.5|b,15|c, etc., being there connected, each toits individual selector valve.

Figs. 5 and 6 show the selective valve mechanism by means ofv which a plurality of the shutoff hose'36 are controlled. It comprises a base 62 which supports a control panel 63 upon which is mounted a pressure regulating valve 64 of the type having a body 66, a pressure inlet 68, a pressure outlet 18, a gauge 'I2 indicating the pressure at the inlet, a gauge indicating thev pressure atV the outlet and a control handle 'I6 for regulating the foutlet pressure.

1 Mounted also on the panel 64 are a series of selector valves-Ba, 88h, 88e, etc., ofthe type consisting of a body 18 containing a cylindrical plug 82 rotatable through one-quarter turn by a handle 84. The. body I8 has an inlet port 85, an outlet port 88 located ninety degrees from the inlet port, and a relief port V98 located ninety degrees-from the outlet-port. The rotatable plug 82 has a port 92, the inlet and outlet end of which span ninety degrees, whereby when the valve is turned to the position shown: at 94, the inlet and outlet ports 86 and 88 are connected, and when the valve is turned to the positionshown at 96, the outlet portllA and the relief port 98 are connected. f

The inlet 68 of the pressure regulating valve 64 is connected to any suitable source of pressure bytubing 98, while the outlet 18 is connected to the inlet port 86 of all of the selector valves in parallelby tubing |88. A cover |02 enQ1Q-hB control panel mechanism.

The operation of the mechanism in determining pressure distribution is as follows:

The number of test points in a section of the wing surface in the example shown is 28 and there are 12 sections. Since the valve block assemblies have fourteen valves, a group of two blocks in series takes care of one wing section, and a stack of these groups twelve high takes care of the twelve Wing sections.

Holes are provided in the wing skin at the desired test points and relatively short lengths of tubing |84 are used to connect the inner side of these holes to the nipples 28 of the valve block assemblies. The top row of Y connectors 32 are then plugged, intermediate the top and bottom rows the ends designated 32 are connected to the ends designated 34 by short lengths of exible tubing |86, and the bottom row of ends designated 34 are connected' to the individual manometer Ytubes 54a, 5419, etc. All selector valves 88a, 88h,

etc., are turned to the position 94 whereby pressure is conveyed toi all shut-01T hose 36 to bring them to circular cross section and the individual valves of all the valve block assemblies are closed.

Turning any one of the twelve selector valves, as for instance turning the selector valve 88h, to the position 96, will cut oli the pressure to the group of valves in the Vvalve block assemblies 58B and 58h, whereupon the flat springs 38 will return theshut-oif hose to the ovate form of 'ig.l 2 and the valves in valve block assemblies 58B and 58h will be open and the openings in the second wing tion 94 to the position 96 then back to the positionY 94, the manometer tubesr will have recorded 4the pressures on the wing surfaces at all of thetest openings, one group'at a time.VV Ivclaim:

1 "For determining the air pressure distribution on the surface of an airfoil or the like, the apparatus which comprises a plurality of manometer tubes, a plurality of valves equal tothe number of points on said surface at which. the pressure is to be evaluated, said valves being arranged in groups, each group having a number of valves equal to the number of manometertubes, a plu: rality of control means equal to the number of groups, Aeach control means being constructed and arranged to operate all the valves of one group simultaneously, conduit means for connecting the manometer tubes to one side of the valves of a group, and conduit means for connecting each of said points to the other side-0f one of the valves. V

2. For Vevaluating `the Vair pressurel distribution on the surfaceof an airfoil or thelike, the apparatus which comprises a multiple manometer having a pluralityof manometertubes, av plurality of groups of valves together having a number of valves equal to the number of points on said surface at which the pressure is to be evaluated, each group having a number of valves equal to the number of manometer tubes, a remote control means for each group constructed and arranged to operate all of the valves of said group coincidentally, conduit means connecting one side of each valve to one of said points, and conduit means connecting the other side of each group to said manometer tubes in parallel.

3. For determining the distribution of air pressure over the surface of an airfol or the like,.

the apparatus which comprises a, plurality vof valves equal to the number of points on said surface at which the pressure is to be evaluated, said valves being arranged in groups, a plurality of manometer tubes equal in number to the number 10 simultaneously. Y

HERBERT M. HIEUVER. 

